Apparatus for measuring and controlling the amount of size and finish applied to textile yarns and fabrics



Sept. 21, 1965 Filed July 23, 1962 C. F. STRANDBERG, JR

APPARATUS FOR MEASURING AND CONTROLLING THE AMOUNT OF SIZE AND FINISHAPPLIED TO TEXTILE YARNS AND FABRICS D.C.Power 3 Sheets-Sheet l INVENTORCHARLES F. STRANDBERG,Jr.

/7 7 I 1 BY 7? A cw ATTORNEY Sept. 21, 1965 c. F. STRANDBERG, JR 3,

APPARATUS FOR MEASURING AND CONTROLLING THE AMOUNT OF SIZE AND FINISHAPPLIED TO TEXTILE YARNS AND FABRICS Filed July 25, 1962 I5 Sheets-Sheet2 T 2| D.C.Power 20 p 42 6V.AC ll5V.A.C. l9

3 33$ K INVENTOR l LI CHARLES F. STRAND/BERGJL E BY ATTORNEY Sept. 21, 1

Filed July 23, 1962 C. F. STRANDBERG, JR APPARATUS FOR MEASURING ANDCONTROLLING THE AMOUNT OF SIZE AND FINISH APPLIED TO TEXTILE YARNS ANDFABRICS 5 Sheets-Sheet 3 |OO I Constant 34 Pressure 35 Air Supply I 31Pneumatic j Controller 32 I INVENTOR CHARLES F. STRANDBERG,Jr.

ATTORNEY United States Patent 3,207 ,125 APPARATUS FOR MEASURING ANDCONTROL- LING THE AMOUNT OF SIZE AND FINISH APPLIED TO TEXTILE YARNS ANDFABRICS Charles F. Strandberg, Jr., Greensboro, N.C., assignor toStrandberg Engineering Laboratories, Inc., Greensboro, N.C., acorporation of North Carolina Filed July 23, 1962, Ser. No. 211,508 6Claims. (Cl. 118-4) The present invention relates to a method andapparatus for continuously measuring and controlling the amount of sizeor finish material applied to textile yarns and fabrics in a slasher orother coating machine.

Before textile warp yarns are woven into fabric, they are usuallyslashed or sized, a process which applies a starch to the yarns for thepurpose of protecting them against the abrasive actions of the loom.

Similarly, various finished compounds, including size, are added towoven and knitted fabrics for the purpose of increasing weight, surfacequality, and durability in use.

The sizing and finishing processes are generally the same. The web isimmersed in a liquid bath containing starch or some other compound. Itis then passed between squeeze rolls, which extract the excess liquid,and on to a dryer section, which evaporates the water portion but leavesthe starch or finish solids in or attached to the warp yarns or fabric.

Knowledge and control of the percentage of solids added to the web arevery important, but there has been no satisfactory known method forcontinuously measuring it. Samples of the web, at present, must be cutout and applied to chemical separation processes, one of which iscommonly known in the industry as de-sizing, in order to determine thepercent solids added to the net weight of the web. These tests requireconsiderable time to conduct, and the resulting information cannot beused during processing when it is needed most.

Several factors are known to affect the amount and consistency of thesolids picked up. One of these is the percent solids in the liquid bath.This can, of course, be controlled by mixing desired amounts of drysolids with water in preparing the liquid bath. Another factor issqueeze roll pressure. Variations in the amount of liquid left on theweb after squeezing cause corresponding variations in the solidsretained after evaporation of the water portion in the dryer section.

Various other factors are contributory. Variations in viscosity andtemperature affects solids pickup. These are often held constant for thepurpose of reducing variations in pickup. The moisture content of thedry web, its velocity through the liquid bath and squeeze rolls, and thekind of fibers making it up also influence solids pickup.

As a means for determining approximate pickup over a period of time,some mills gauge the volume of liquid consumed against the weight of webprocessed. With this knowledge of the percent solids in the liquid, theyare able to calculate the average solids pickup. The method is, again,time consuming and does not provide any information about theinstantaneous pickup.

Some work has been done with electric capacitance measuring devices,which indicate the approximate weight of entering web and the dried web.Except for differences in moisture content, the difference between inputweight and output weight is equal to the solids added. Due to theinfluence of moisture content upon the capacitance measurement, themethod is not known to have been satisfactorily applied in a practicalinstallation.

The measurement method employed in the apparatus of this inventionutilizes the measurement of the liquid 3,207,125 Patented Sept. 21, 1965added to the web. Since the percentage of solids in the liquid areusually known and controlled by regulated mixing procedures, it followsthat the net solids picked up are in the same manner related to thetotal liquid picked up by the web. The relationship holds true, sincethe solids form a known part of the homogenous liquid, the relativeparts of which are unchanged by squeezing.

The measurement on the web is made directly after squeezing prior to anyevaporation due to drying. The effect of drying is, of course, to upsetthe known relationship between water and solids by evaporating the waterportion without affecting the solids.

It is an object of the invention to provide a method and means forcontinuously measuring the amount of liquid added to the textile yarn orweb in a slasher or other coating machine.

It is a further object of this invention to provide means toautomatically control the amount of liquid added to the textile yarn orweb according to the deviation of the measured amount of added liquidfrom a predetermined desired quantity of added liquid.

It is a further object of this invention to provide electricalconductivity measuring means for measuring the electrical conductivityof textile yarn or web after it has been treated with a treating liquidand indicating means for indicating the amount of added liquiddetermined as a function of the electrical conductivity of the treatedyarn or web.

It is a further object of this invention to correct the electricalconductivity measurement of the liquid treated yarn or web in accordancewith variations in the electrical conductivity of the treating liquid.

It is a further object of this invention to provide improved motorcontrol means for automatically regulating the amount of treating liquidadded to the material to be treated.

It is to be understood that the use of the term conductivity in thistext has reference to electrical conductivity even though the wordelectrical is omitted.

With the foregoing objects and features in view and such other objectsand features as may become apparent as this specification proceeds, theinvention will be understood from the following description taken inconjunction with the accompanying drawings, wherein like characters ofreference are used to designate like parts, and wherein:

FIGURE 1 is a diagrammatic representation of a textile finishing machineand the apparatus for measuring the amount of finishing liquid appliedto the textile yarn or fabric with manual means for setting in acorrecting factor for the conductivity of the finishing liquid.

FIGURE 2 is similar to FIGURE 1 but includes automatic means for settingin a correcting factor providing for variations in the conductivity ofthe finishing liquid.

FIGURE 3 is a diagrammatic representation of one form of apparatusprovided for automatically controlling the pressure of the squeeze rollsof the slasher used in this invention.

FIGURE 4 is a diagrammatic representation of another form of apparatusprovided for automatically controlling the pressure of the squeeze rollsof the slasher used in this invention.

Referring to FIGURE 1, untreated web 1 travels from the beam 2 over theguide roll 3 into the sizing liquid 4 in tank 5 and under the immersionroll 6. The web 7, now soaking wet with liquid, passes between thesqueeze rolls 8 and 9. After squeezing, the excess liquid has beenremoved from the web, the weight of which has increased 50 to 200percent due to the added weight of the liquid. The wet web 10 thencontacts detector roll 11, one of the measuring elements of theinstrument, and passes over a set of hot dry cans 12, which cause thewater portion of the liquid on and in the web to evaporate. The speed of3 .he machine and the surface temperatures of the dry cans are set sothat the moisture in the web 13 is about the same as prior toprocessing. The sized or finished web is then wound on beam 14.

The apparatus described in the paragraph above with the exception ofdetector roll 11 is included in conventional slashers known in thetextile industry.

The measuring circuit of this invention, consisting of a pair of spaceddetector electrodes including grounded squeeze roll 9and detector roll11, the portion of the size treated web 10 contacting and interveningthe grounded squeeze roll 9 and detector roll 11, variable resistor 15,current limiting resistor '16, and the 6.3 volt transformer 17, isbasically an A.C. conductivity measuring circuit. The two positionswitch 18 is a standardize-operate switch having two fixed contacts 18aand 18b engaged by the movable arm 18. Contact 18a is connected in astandardize circuit including a pair of spaced electrode probes 38 and39 immersed in the liquid 4, the secondary Winding 21 of transformer 17,current limiting resistor 16, variable resistor and the movable contact18'. The function of the standardize circuit is to enable adjustment ofthe variable resistor 15 in order to correct the measuring circuit forthe conductivity of the liquid 4 in the tank 5.

Contact 18b is connected in a measuring or operating circuit, includingthe metal detector roll 11, the length of liquid moistened web or yarn22, between roll 11 and roll 9, the grounded metal squeeze roll 9, thesecondary winding 21 of transformer 17, resistor 16, variable resistor15, and movable contact 18'. With switch 18 in the position shown,current from the fixed A.C. voltage source 19 across the secondaryWinding 21 of transformer 17 flows through the series resistors 16 and15, through the switch 18, through the web portion 22 between thedetector roll 11 and the metal squeeze roll 9, and returns to thesecondary Winding 21 of transformer 17.

The conductivity of the Web portion 22 subjected to current flow is afunction of both the amount of liquid added and the conductivitycharacteristic of the liquid.

The A.C. voltage developed across variable resistor 15 and currentlimiting resistor 16 is then a function of the amount of liquid on theweb and the conductivity characteristics of the liquid.

A representative portion of the voltage developed across resistors 15and 16 is selected by the potentiometer 23 and is applied through thecoupling capacitor 24 to a conventional A.C. voltage amplifierconsisting of grid resistor 25, vacuum tube 26, cathode resistor 27,cathode by-pass capacitor 28, audio output transformer 29, and the DC.power supply 42. The A.C. voltage developed in the output or secondarywinding 29 of the transformer 29 is then rectified by diode 30, filteredand dampened by capacitor 31 and is applied to the measuring instrumentcoil 32.

Referring to FIGURE 3', by way of illustration, but not restrictedthereto, the measuring instrument coil 32 may be a circuit element of aconventional electric-to-air transducer in a pneumatic controller 33.The coil current produces a corresponding and proportional change in anorifice opening, which regulates the air pressure from a constant airsource 34 to be applied to a conventional pneumatic recording instrument35, and for control purposes, to diaphragm pneumatic motors 36, 37 of aconventional pneumatically loaded squeeze roll set 8 and 9, the pressureof which is air controlled and is a function of the input electricsignal.

The upper roll 8 of the squeeze roll set is movable vertically relativeto the bottom roll 9 by means of the diaphragm pneumatic motor 36, 37.

The pneumatic controller 33 may be an instrument combining a controllerand recorder in one unit, such as Taylor Instrument Companys pneumaticrecording controller Type No. 122 R F 137. In the device a known airsignal is applied and is called a set point. The unknown signal from anelectric-to-air transducer then causes the output pressure applied tothe pneumatic actuators 36 and 37 to vary the squeeze roll pressure inthe correction direction until the unknown air signal is equal to theset point signal.

The A.C. conductivity measurement of the wet Web 10 is dependent uponboth the amount of liquid added and the conductivity characteristics ofthe liquid 4. It is necessary to take into account the conductivitycharacteristics of the liquid, since this is subject to variation fromtime to time.

Liquid conductivity is related to the total ion content. The acidity oralkalinity of a liquid is commonly expressed in terms of pH, a numberwhich is equal to the logarithm of the reciprocal of the positivehydrogen ion content. pH alone is, therefore, not related to A.C.conductivity through a liquid. Total conductivity is related to both thepositive hydrogen ion content and the negative hydroxide ion content.Certain salts, for instance, when added to liquids may affect pH tonegligible extents while total ion content and total conductivity may beappreciably affected.

The relationship between the conductivity between probes 38, 39, FIGURE1, immersed in sizing liquid 4 and the conductivity through ahygroscopic Web of textile fibers 22 between metallic detector elementsor rolls was determined by experiment. It was determined that for eachamount of liquid added to the web, the ratio of liquid conductivity towet web conductivity is constant, each, of course, being dependent uponconstant temperature.

The method, therefore, employed in the measuring apparatus to eliminatethe effect of pH, salts, and any other factors which affectconductivity, so as to establish an exact relationship with total liquidpickup only, includes the use of a set of immersion probes in the liquidbath. Selector switch 18 is employed for the purpose of measuring theliquid conductivity between the probes 3 8 and 39 in the same manner asbetween the detector roll 11 and the squeeze roll 9.

When the operate-standardize selector switch movable contact 18' ismoved to engage contact 18a, probes 38 and 39 are then in series circuitwith the secondary winding 21 of the transformer 17, and with resistors15 and 16. The A.C. voltage appearing across resistors 15 and 16 istherefore a function of the conductivity of the liquid bridging theprobes 38 and 39.

The constant ratio is, of course, dependent upon the physical spacingand exposure dimensions of both the immersion probes 38, 39 and thedetector roll 11 and squeeze roll 9. For an experimental installation,the ratio was determined to be 17:1, the liquid conductivity being 17times the wet web conductivity.

Once the ratio has been determined for a given installation and theindicating and recording instrument calibrated to read in percent totalwet pickup or percent solids pickup, any changes in pH, salt content, orother influencing factors in the liquid bath, can be measured and theinstrument recalibrated to eliminate the effect of the aforesaidchanges.

Variable resistor 15 is calibrated in units of conductivity and is usedto set the instrument to read the wet web conductivity correctly, takinginto account the liquid conductivity.

A.-C.- conductivity is employed instead of D.-C. conductivity in orderto avoid the effects of polarization of the immersion probes. D.-C.measurements can be used on the web, since the detectors are in constantmotion.

The setting of the variable resistor 15 can be made by calculation,using the ratio determined, or it can, by various means, not shown, beset automatically. Such an automatic standarization means could beaccomplished by the use of a control motor linked to a balancingpotentiometer or an amplifier stage could be incorporated in such amanner that it will present an impedance in one, circuit in constantratio with another.

The variable resistor 23 is used as a factor to account for the knownpercent solids in the liquid so that the chart or meter scale ofrecorder 35 can be calibrated directly in terms of percent solids addedto the web.

Referring now to FIGURE 2, I have shown one preferred means forautomatically correcting the measurement of the conductivity of theliquid treated web 22 between detector roll 11 and squeeze roll 9 tocompensate for variations in the conductivity of the liquid.

The description previously given, which applies to FIG- URE 1, is thesame for FIGURE 2, except that two additional ganged switch sections 40and 41 having movable contacts 40' and 41' respectively, standardizecontacts 40a and 4111 respectively, and operate contacts 40b and 41brespectively are added to the operate-standardize switch 18 alreadydescribed. These additional switch sections merely permit the immersionprobes 38 and 39 to be connected to an automatic standardization circuit44 when the ganged switch is in the operate position as shown.

When the movable contacts 18', 40 and 41 are engaged respectively withthe standardize contacts 18a, 40a, 41a, the standardize circuit is thesame as that described for FIGURE 1 except for the addition of theswitch sections 40 and 41. The apparatus shown in FIGURE 2 is presetprior to operation of the measuring and automatic standardizing meanssubsequently to be described by adjusting the resistor to correct forconductivity of liquid 4 in the same way as has been described withrespect to the apparatus shown in FIGURE 1. Any variation in theconductivity of the sizing liquid 4 after resistor 15 has been presetwill be corrected by the automatic standardizing circuit 44.

The conductivity measuring circuit 43 and the automatic standardizingcircuit 44 are closed when the movable switch contacts 18, 40', 41'engage contacts 18b, 40b, 41b in the operate position.

The conductivity measuring circuit in the operate position of switch 18is exactly the same as shown in FIG URE 1 and includes in series circuitcontact 1812, the detector roll 11 the length of liquid moistened web oryarn 22 between roll 11 and roll 9, the grounded metal squeeze roll 9,the secondary 21 of the transformer 17, resistor 16, variable resistor15 and movable contact 18.

The object of standardization of the wet fabric or warp conductivityagainst the liquid wetting agent conductivity is, as previouslyexplained, to maintain a constant ratio of one conductivity level to theother. Once the instrument is calibrated to record percent wet pickup orpercent sizing correctly on the basis of the correlation between theamount of liquid on the web and its electrical conductivity, any changesin the liquid conductivity will, of course, require a compensatingchange to be made in the setting of the variable resistor 15. In thisway, changes in the conductivity of the wetting agent will not beerroneously recorded as changes in the amount of liquid applied to theweb.

The automatic means of standardization shown in FIG- URE 2 provides formaking a direct change in the current in the coil 32 which actuates therecording instrument in a magnitude which corresponds exactly with thatwhich would otherwise be made in the setting of the variable resistor15. In this way, the setting of the variable resistor 15 is notautomatically controlled and is left in its preset position.

With the switch 18 and ganged sections 40 and 41 in the operate positionas shown, the A.-C. voltage developed across variable resistor 15 andcurrent limiting resistor 16 is amplified by vacuum tube 26 and appliedto the recorder 35 through coil 32 as a function of both the amount ofliquid on the web and the conductivity of the liquid. The elTect ofvariations in the conductivity of the liquid is then eliminated byapplying an opposing current through the coil 32 as a direct function ofthe liquid conductivity alone.

6. This is accomplished by connecting the immersion probes 38 and 39 ina voltage divider combination consisting also of an adjustableresistance 45 and series-connected, current limiting resistor 46.Voltage is supplied to the dividerfrom the secondary winding 47" oftransformer 47. Voltage is supplied to the primary 47 of transformer 47from A.-C. voltage source 48. At the time of initial calibration, thetotal resistance of the adjustable resistor 45 and current limitingresistor 46 is set to a value which is equal to the resistance betweenthe probes 39 and 38. Under this condition, the A.-C. voltage developedacross the probes 38 and 39 will cause current to flow through the diode49 and resistor 50.

Since the resistance value of resistor 51 is the same as that ofresistor 50 and since equal values of A.-C. voltage are applied throughcorresponding diodes 49 and 52, the resulting D.-C. voltages developedacross resistors 50 and 51 will be equal and their common terminals 53,53 will be negative with respect to their opposite terminals 55, 56.Capacitors 57 and 58 are provided for smoothing the voltage developedacross resistors 50 and 51 respectively.

As the conductivity of the liquid changes, the voltages developed acrossresistors 50 and 51 will change so that a net diiference voltage will beapplied in series with the coil 32. Depending upon the polarity of thedifference voltage, the coil current will be made to increase ordecrease.

It can be seen that an increase in liquid conductivity will cause adecrease in A.-C. voltage across the probes 38 and 39 and an increase inthe A.-C. voltage developed across the series combination consisting ofthe adjustable resistor 45 and current limiting resistor 46. Therectified D.-C. voltage developed across resistor 50 will then be lowerthan that developed across resistor 51. Summation of the series D.-C.voltage sources applied to the coil 32 consists of the voltage acrosscapacitor 31, which is a function of web conductivity, an opposingvoltage developed across resistor 51, and an aiding voltage developedacross resistor 50. Since the opposing voltage developed across resistor51 is greater than the aiding voltage developed across resistor 50, thecurrent through the coil 32 will be decreased.

Conversely, a decrease in liquid conductivity will result in an increasein the aiding voltage developed across resistor 50 and a decrease in theopposing voltage developed across resistor 51, thus resulting in anincrease in current through the coil 32.

In FIGURE 4 there is disclosed a motorized control valve 70 and controlcircuit effective to regulate the angular position of an existing handcontrol valve in the air line 71 to the pneumatic diaphragm actuators 36and 37. This apparatus takes the place of the pneumatic controllerdevice 33 shown in FIGURE 3 and may be used when it is desirableto'convert a hand controlled air supply system for supplying pneumaticdiaphragm actuators 36 and 37 to a motor controlled air supply system.

The device shown in FIGURE 4 utilizes a photoelectric meter relay 72 tosense a departure from the desired level of wet pickup. The photocells73, 74 actuate relays 75, 76 to cause a control motor 77 to eitherincrease or decrease the valve opening 78 depending upon whether thepickup has increased or decreased from the desired value.

Referring to FIGURE 4, a D.-C. voltage from the output coil 32 (seeFIGURES 1 and 2), already described, is applied across potentiometer 79.A portion of this voltage is applied to the moving coil 80 of athree-position photoelectric meter relay 72. The meter relay 72 consistsof two light sources 81, light shading pointer 82 mechanically attachedto the moving coil 80 and two closely spaced photoelectric cells 73 and74.

The potentiometer 79 is calibrated in terms of Percent Size or PercentWet Pickup corresponding to the value of voltage from the output coil 32which will cause the D.-C. voltage selected by the potentiometer 79 tobe such that the light shading pointer 82 of the photoelectric meterrelay 72 will be positioned precisely between the light beamsilluminating the two photoelectric cells 73 and 74.

When the measured pickup increases from the desired value set on thepotentiometer 79, the light shading pointer 82 will move upward andshade the light from the upper photoelectric cell 74. Similarly, whenthe measured pickup decreases from the desired value set on thepotentiometer 79, the light shading pointer will move downward and shadethe light from the lower photoelectric cell 73. Mechanical stops (notshown) are employed so the pointer 82 cannot travel beyond thecompletely shaded positions of each photoelectric cell.

The photoelectric cell 73 is connected in series with resistor 83 acrossthe A.-C. line 85. Similarly, photoelectric cell 74 and resistor 84 inseries are connected across A.-C. line 85.

The voltage developed across the photoelectric tube 73 is applied fromthe control grid 87 to the cathode 88 of a gas control tube 86.Similarly, the voltage developed across the photoelectric tube 74 isapplied from the control grid 91 to the cathode 92 of gas control tube90. The cathode 88 and anode 89 of gas control tube 86, and the cathode92 and anode 93 of the gas control tube 90 are connected respectively inseries with coil 75' of plate relay 75 and coil 76' of plate relay 76across the A.C. line 85.

When the cell 73 is illuminated, its resistance is low, and the A.-C.voltage developed across it is low. When the cell 73 is shaded, as wouldbe caused by a decrease in wet pickup, the cell resistance is high, andthe A.-C. voltage developed across it is high.

Since the A.-C. voltage developed across the photoelectric cell 73 isapplied from the control grid 87 to the cathode 88 of gas control tube86, the tube 86 will conduct when its grid 87 and anode 89 are positivewith respect to its cathode 88.

Since plate relay 75 is connected in the anode circuit of the gascontrol tube 86, it is energized by a decrease in wet pickup below thevalue set on the potentiometer 79. The energization current is pulsatingD.-C. rectified and passed by the tube 86.

As described, when the upper photoelectric cell 74 is shaded, as causedby an increase in wet pickup, the grid to cathode voltage applied to thesecond gas control tube 90 is increased sufiiciently to cause conductionin its anode circuit through plate relay 76.

Similar resistor-capacitor networks comprising resistor 94 and capacitor95 in series, and resistor 96 and capacitor 97 in series are connectedacross the plate relay coils 75 and 76, respectively, for the purpose ofproviding' filtering of the pulsating D.-C. current.

When the wet pickup is equal to the value set on the potentiometer 79,the low-pickup relay 75 and the highpickup relay 76 are bothde-energized. When the Wet pickup is low, the low-pickup relay 75 isenergized and the high-pickup relay 76 is de-energized. When the wetpickup is high, the high-pickup relay 76 is energized and the low-pickuprelay 75 is de-energized.

The upper set of contacts 75a, 76a associated with relays 75 and 76,respectively, serves to operate signal lights 98, 99 to show when thecontrol is measuring a deviation from the preset value set onpotentiometer 79 and in which direction the control is acting to correctit. Ordinary neon indicator lamps 98 and 99 are employed with currentlimiting resistors 100 and 101.

The lower sets of contacts 75b, 76b associated With relays 75 and 76respectively, close the control motor 77 circuit from common 102 toincrease or decrease, depending upon the direction of deviation in wetpickup. When the pickup is determined to be low with respect to setpoint on the potentiometer 79, the control motor 77, through mechanicallinkages 103 reduces the valve opening 78 so as to apply less pressureto the squeeze or pad roll actuators 36, 37. Similarly, when the pickupis high, the control motor 77 increases the valve opening 78 so as toapply greater pressure to the roll actuators and thereby reduce thepickup.

While, in the foregoing description, there have been described and shownthe preferred embodiments of the invention, various modifications maybecome apparent to those skilled in the art towhich the inventionrel-ates. Accordingly, it is not desired to limit the invention to thisdisclosure and various modifications and equivalents may be resorted to,falling within the spirit and scope of the invention as claimed.

I claim:

1. In a textile machine having means feeding a strip of connectedtextile fibers therethrough, means imparting liquid size to the strip ofconnected textile fibers, means varying the amount of liquid sizeretained by the strip, and means receiving the size treated strip; theimprovement comprising electrical conductivity measuring means includinga pair of spaced detector electrodes contacting said size treatedtextile strip and connected in circuit with an electric voltage sourceto pass an electric current through the size treated textile stripintervening said detector electrodes for measuring the electricalconductivity of the size treated strip of connected textile fibers,electrical conductivity measuring means for measuring the electricalconductivity of said liquid size, means correcting the electricalconductivity measurement of said size treated strip of connected textilefibers for variations in electrical conductivity of the liquid size,means utilizing the corrected electrical conductivity measurement ofsaid size treated strip of connected textile fibers for controlling themeans varying the amount of liquid size retained by said strip ofconnected textile fibers.

2. Measuring apparatus for determining the amount of size retained in astrip of connected textile fibers being treated in a textile machinehaving means feeding a strip of connected textile fibers therethrough;said apparatus comprising means imparting liquid size to the strip ofconnected textile fibers, and means receiving said strip after liquidsize is imparted thereto, said measuring apparatus including electricalconductivity measuring means including a pair of spaced detectorelectrodes contacting said size treated textile strip and connected incircuit with an electric voltage source to pass an electric currentthrough the size treated textile strip intervening said detectorelectrodes for measuring the electrical conductivity of the size treatedstrip of connected textile fibers, electrical conductivity measuringmeans for measuring the electrical conductivity of said liquid size,means for applying a correction factor to said electrical conductivitymeasurement of said size treated strip of connected textile fibers toaccount for the electrical conductivity of the liquid size, and meansresponsive to the corrected measurement of the electrical conductivityof said treated strip of connected textile fibers for indicating theamount of size retained in said size treated strip, the amount of sizeretained being in a direct function of said corrected electricalconductivity measurement.

3. A sizing machine for strips of textiles or the like having squeezerolls for varying the amount of size retained on the textile strips,comprising in combination pneumatic actuators for controlling thepressure applied by said squeeze rolls on said textile strips, valvemeans for controlling the pneumatic pressure applied to said actuators,and an electric control motor for controlling said valve means, electricmeasuring means including a pair of spaced detector electrodescontacting said size treated textile strip and connected in circuit withan electric voltage source to pass an electric current through the sizetreated textile strip intervening said detector electrodes for producingan electric voltage signal proportional to the amount of size retainedon said textile strip, control means for said electric control motorincluding a three position photoelectric meter relay connected to saidelectric measuring means, the three positions of said meter relaycorresponding respectively to a predetermined low quantity of retainedsize, a predetermined correct quantity of retained size and apredetermined high quantity of retained size, an increase circuit forsaid control motor for energizing said control motor in a direction toactuate said valve to decrease the pneumatic pressure applied to saidpneumatic actuators, and a decrease circuit'for said control motor forenergizing said control motor in a direction to actuate said valve todecrease the pneumatic pressure applied to said pneumatic actuators,means responsive to said low quantity position of said photoelectricmeter relay for energizing said decrease circuit, and means responsiveto said high quantity position of said photoelectric meter relay forenergizing said increase circuit, said motor being de-energized whensaid photoelectric meter relay is in the correct quantity position.

4. A Web coating machine measuring apparatus for determining the amountof liquid coating material retained on the liquid coated web, comprisingin combination electrical conductivity measuring means including a pairof spaced detector electrodes contacting said liquid coated web andconnected in circuit with an electric voltage source to pass an electriccurrent through the liquid coated web for measuring the electricalconductivity of the liquid coated web, electrical conductivity measuringmeans for measuring the electrical conductivity of said liquid coatingmaterial, means for applying a correction factor to said electricalconductivity measurement of said liquid coated web to account for theelectrical conductivity of the liquid coating material, and meansresponsive to the corrected measurement of the electrical conductivityof said liquid coated web for indicating the amount of coating materialretained on said web.

5. The apparatus as set forth in claim 4 wherein said means for applyinga correction factor to said electrical conductivity measurement of saidliquid coated web to account for the electrical conductivity of theliquid coating material is automatic.

6. A sizing machine for strips of textiles or the like, having means forvarying the amount of size retained on the textile strips, comprising incombination fluid motors for controlling the means for varying theamount of size retained on the textile strips, valve means forcontrolling the fluid applied to said fluid motors and an electriccontrol motor for controlling said valve means, electric measuring meansincluding a pair of spaced detector electrodes contacting said sizetreated textile strip and connected in circuit with an electric voltagesource to pass an electric current through the size treated textilestrip intervening said detector electrodes for producing an electricvoltage signal proportional to the amount of size retained on saidtextile strip, control means for said electric control motor including athree position photoelectric meter relay connected to said electricmeasuring means, the three positions of said meter relay correspondingrespectively to a predetermined low quantity of retained size, apredetermined correct quantity of retained size and a predetermined highquantity of retained size, an increase circuit for said control motorfor energizing said control motor in a direction to actuate said valveto increase the fluid pressure applied to said fluid actuators, and adecrease circuit for said control motor for energizing said controlmotor in a direction to actuate said valve to decrease the fluidpressure applied to said fluid actuators, means responsive to said lowquantity position of said photoelectric meter relay for energizing saiddecrease circuit, and means responsive to said high quantity position ofsaid photoelectric meter relay for energizing said increase circuit,said motor being de-energized when said photoelectric meter relay is inthe correct quantity position.

References Cited by the Examiner UNITED STATES PATENTS 2,215,805 9/40Wills 324 2,263,017 11/41 Sparrow 32465 2,558,392 6/51 Seney 32465 XR2,615,822 10/52 Huebner 1l747 2,703,386 3/55 Seney 32465 2,942,352 6/60Eicken-Estienne 32465 XR 2,956,905 10/60 Jones et al. 118-9 2,977,9254/61 Norton 1l766 XR WILLIAM D. MARTIN, Primary Examiner.

RICHARD D. NEVIUS, Examiner.

1. IN A TEXTILE MACHINE HAVING MEANS FEEDING A STRIP OF CONNECTEDTEXTILE FIBERS THERETHROUGH, MEANS IMPARTING LIQUID SIZE TO THE STRIP OFCONNECTED TEXTILE FIBERS, MEANS VARYING THE AMOUNT OF LIQUID SIZERETAINED BY THE STRIP, AND MEANS RECEIVING THE SIZE TREATED STRIP; THEIMPROVEMENT COMPRISING ELECTRICAL CONDUCTIVITY MEASURING MEANS INCLUDINGA PAIR OF SPACED DETECTOR ELECTRODES CONTACTING SAID SIZE TREATEDTEXTILE STRIP AND CONNECTED IN CIRCUIT WITH AN ELECTRIC VOLTAGE SOURCETO PASS AN ELECTRIC CURRENT THROUGH THE SIZE TREATED TEXTILE STRIPINTERVENING SAID DETECTOR ELECTRODES FOR MEASURING THE ELECTRICALCONDUCTIVITY OF THE SIZE TREATED STRIP OF CONNECTED TEXTILE FIBERS,ELECTRICAL CONDUCTIVITY MEASURING MEANS FOR MEASURING THE ELECTRICALCONDUCTIVITY OF SAID LIQUID SIZE, MEANS CORRECTING THE ELECTRICALCONDUCTIVITY MEASUREMENT OF SAID SIZE TREATED STRIP OF CONNECTED TEXTILEFIBERS FOR VARIATIONS IN ELECTRICAL CONDUCTIVITY OF THE LIQUID SIZE,MEANS UTILIZING THE CORRECTED ELECTRICAL CONDUCTIVITY MEASUREMENT OFSAID SIZE TREATED STRIP OF CONNECTED TEXTILE FIBERS FOR CONTROLLING THEMEANS VARYING THE AMOUNT OF LIQUID SIZE RETAINED BY SAID STRIP OFCONNECTED TEXTILE FIBERS.